US2025264703A1PendingUtilityA1
Zoom lens and image pickup apparatus
Est. expiryFeb 20, 2044(~17.6 yrs left)· nominal 20-yr term from priority
Inventors:Akihiko Yuki
G02B 15/1461G02B 15/20
57
PatentIndex Score
0
Cited by
0
References
0
Claims
Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit with positive refractive power that does not move during zooming, at least two movable lens units that move during zooming, and a final lens unit with positive refractive power that does not move during zooming. A distance between adjacent lens units changes during zooming. The first lens unit includes at least one negative lens and at least one positive lens. A predetermined inequality is satisfied.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1 . A zoom lens comprising, in order from an object side to an image side:
a first lens unit with positive refractive power that does not move during zooming; at least two movable lens units that move during zooming; and a final lens unit with positive refractive power that does not move during zooming, wherein a distance between adjacent lens units changes during zooming, wherein the first lens unit includes at least one negative lens and at least one positive lens, and wherein the following inequality is satisfied:
10.
≤
vp
1
≤
17.4
where νp1 is an Abbe number based on d-line of a first positive lens included in the at least one positive lens.
2 . The zoom lens according to claim 1 , wherein the following inequality is satisfied:
1.95
≤
Np
1
≤
2.35
where Np1 is a refractive index of the first positive lens for the d-line.
3 . The zoom lens according to claim 1 , wherein the first lens unit includes, in order from the object side to the image side, a first subunit with negative refractive power, a second subunit with positive refractive power, and a third subunit with positive refractive power, and
wherein during focusing, the first subunit does not move, and at least the second subunit among the second subunit and the third subunit moves.
4 . The zoom lens according to claim 3 , wherein the first positive lens is included in the first subunit.
5 . The zoom lens according to claim 3 , wherein the first subunit includes at least one negative lens, and
wherein the following inequalities are satisfied:
5
≤
vn
1
ave
-
vp
1
≤
40
-
0.0065
≤
(
θ
n
1
ave
-
θ
p
1
)
/
(
vn
1
ave
-
vp
1
)
≤
-
0.0025
where vn1 ave is an average Abbe number based on the d-line of the negative lens in the first subunit, θn1 ave is an average partial dispersion ratio for g-line and F-line of the negative lens in the first subunit, and θp1 is a partial dispersion ratio for the g-line and the F-line of the first positive lens.
6 . The zoom lens according to claim 3 , wherein the first subunit includes at least one negative lens, and
wherein the following inequality is satisfied:
0.4
≤
fn
1
/
f
11
≤
2.
where fn1 is a focal length of a negative lens closest to an object among the at least one negative lens of the first subunit, and f11 is a focal length of the first subunit.
7 . The zoom lens according to claim 3 , wherein the first subunit includes at least one negative lens, and
wherein the following inequality is satisfied:
-
6.
≤
fp
1
/
f
11
≤
-
0.6
where fm1 is a focal length of a negative lens closest to an object among the at least one negative lens of the first subunit, and f11 is a focal length of the first subunit.
8 . The zoom lens according to claim 1 , wherein the following inequality is satisfied:
2.5
≤
ft
/
f
1
≤
5.
where f1 is a focal length of the first lens unit, and ft is a focal length of the zoom lens at a telephoto end.
9 . The zoom lens according to claim 1 , wherein at least one of the at least two movable lens units has negative refractive power, and
wherein the following inequality is satisfied:
1.
≤
❘
"\[LeftBracketingBar]"
f
1
/
f
2
❘
"\[RightBracketingBar]"
≤
6.
where f1 is a focal length of the first lens unit, and f2 is a focal length of a movable lens unit closest to an object among the at least one movable lens unit having negative refractive power.
10 . The zoom lens according to claim 1 , wherein at least one of the at least two movable lens units has negative refractive power,
wherein a movable lens unit closest to an object of the at least one movable lens unit with negative refractive power includes a negative lens, and wherein the following inequalities are satisfied:
60
≤
vn
2
≤
105
-
0.002
≤
θ
n
2
+
0.001
×
vn
2
-
0.603
≤
0.05
where vn2 is an Abbe number based on the d-line of the negative lens closest to the object of the movable lens unit, and θn2 is a partial dispersion ratio for g-line and F-line of the negative lens closest to the object of the movable lens unit.
11 . The zoom lens according to claim 1 , wherein at least one of the at least two movable lens units has negative refractive power,
wherein a movable lens unit closest to an object of the at least one movable lens unit with negative refractive power includes a second positive lens, and wherein the following inequalities are satisfied:
20
≤
vp
2
≤
40
0.648
≤
θ
p
2
+
0.00253
×
vp
2
≤
0.68
where νp2 is an Abbe number based on the d-line of the second positive lens, and θp2 is a dispersion ratio for g-line and F-line of the second positive lens.
12 . An image pickup apparatus comprising:
a zoom lens, and an image sensor configured to image an object through the zoom lens, wherein the zoom lens includes, in order from an object side to an image side: a first lens unit with positive refractive power that does not move during zooming; at least two movable lens units that move during zooming; and a final lens unit with positive refractive power that does not move during zooming, wherein a distance between adjacent lens units changes during zooming, wherein the first lens unit includes at least one negative lens and at least one positive lens, and wherein the following inequality is satisfied:
10.
≤
vp
1
≤
17.4
where νp1 is an Abbe number based on d-line of a first positive lens included in the at least one positive lens.Join the waitlist — get patent alerts
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